Charter schools play a pivotal role in our conversations about public education. Under the Chicago Public Schools initiative Renaissance 2010 we've seen an expansion of charters over the past decade or so. The latest edition of the independent newsmagazine Catalyst Chicago re-visits Renaissance 2010 and examines how charter schools are performing. There are serious concerns. A Catalyst analysis found that half of Chicago charters have run deficits in recent years. But that doesn't capture the whole story, according to The Illinois Network of Charter Schools.